Presented By
Md. Habibul Islam Hamdu
Deprtment Of Marketing
Hamdard University Bangladesh
Input Devices
Topics
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Keyboard
Mouse
Touch screen
Light pen
Joysticks
Trackball
Bar code reader
OMR
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OCR
Scanner or digitizer
Video digitizer
MICR
Digital camera
Voice or Speech input
system
Uses for which OCR is Suitable
• OCR is used in billing (e.g. gas and electricity bills, insurance
premium renewals) and giro-forms.
• Billing often involves a turn-around document. For example,
electricity bills are prepared in OC by the computer, sent out
to customers who return them with payment checques. The
documents are then re-entered via the OC reader into the
computer system as evidence of payment. Note that no
transcription is needed.
Advantages of OCR
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Key-entry is eliminated and data is captured in machine-readable form at the
earliest opportunity. This should increase throughput and reduce costs and input
errors.
Characters can be read by people.
Document design is less complicated and cumbersome than for OMR forms.
Printing for OCR must meet high standards, and this is expensive.
OCR is economical only when a large number of documents are to be processed.
Only certain types of printed or handwritten characters are recognized.
Document readers are relatively expensive.
Only certain fonts are acceptable.
The reject rate depends on the quality of the document, e.g. smudges, damaged
forms, torn forms, etc.
A high standard of printing is needed.
Hand-printed characters can cause high rejection rates.
Document design must still follow a rigid format.
Situations where OMR is used
• The data to be input is simple;
• The volume of data is large enough to justify designing
documents;
• Turn around documents are used;
• Preparation equipment would be expensive or impractical.
Some examples of uses for where OMR are
suitable
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Multiple-choice examinations, aptitude tests;
Insurance premium collection;
Market research questionnaires - consumer research;
In supermarkets for stock reordering;
Traffic surveys;
Payroll data entry.
Advantages of OMR
• Sensitivity can be altered to allow for different surfaces and
pencils and inks.
• Has a better recognition rate than OCR.
• Can be prepared where data originates, without machines.
• Errors are easily corrected.
Disadvantages of OMR
• Mark readers are relatively slow.
• Verification of marked data is difficult.
• Document may be difficult to understand and fill in or
impractical to design.
• The document reader will have to be reprogrammed for each
new document design.
Uses of bar codes
• On labels on shelves - used for stocktaking, e.g. in factory
stores.
• Printed on shop goods - see supermarket example.
• In libraries - for book and borrower identification.
Advantages
• The characters are easily recognizable to the human being.
• There is high accuracy in reading the characters by the input
device.
• The input devices are reasonable in cost.
• MICR coding is flexible since documents of varying sizes,
thickness and widths can be used without hampering the
processing capability of the reading or sorting equipment.
Digital Camera
•A digital camera (or digicam) is a camera
that takes video or still photographs, or
both, digitally by recording images via an
electronic image sensor.
•Many compact digital still cameras can
record sound and moving video as well
as still photographs.